Coolant deposits

[bteoh]

Did my coolant change over the weekend on my Alfa 75 Potenziata. I think I previously used Castrol green coolant. Flushed it with nulon radiator flush (Ran for 20 mins as per instructions) and then drained coolant.
When I removed the hoses from the thermostat, I noticed some red deposits on the casting. It came off easily with a wire brush but was wondering what it could be. Could it be the previous owner had used red coolant and when I changed it a couple of years ago with Castrol green coolant, a little red coolant could have been left in the system?
Also, anyone have a good idea of how to remove all of the water / coolant in the system? I think some will remain in the block even though I have tried to blow some compressed air.
Filled the system with Nulon green concentrated coolant but it only took 8 litres (4 litres of concentrate coolant and 4 litres of demineralised water) even thought the specs says 10 litres.
Not sure what experiences others have had?

[colcol]

On a good engine like a boxer found in Suds and 33's, they put 1 drain hole in each side of the block, in lesser engines they don't, so you just have to keep flushing with a garden hose until the water comes thru clean, then remove the lowest hose and get out as much water as you can.
Then with your correct ratio of coolant, pour in the coolant slowly from a high hose on the engine, until the coolant starts to dribble out of the lowest hose, then put it back and clamp it up, then start pouring coolant thru until the second lowest hose starts to dribble out coolant, and then do it up, continue doing this until you reach the highest hose, this will help to eliminate air locks.
The red crustations are most likely Red coolant from a previous owner, if they have not cleaned off with the flush, they will most likely stay there, thats why they say don't mix coolants, as sometimes they may mix together and form a sludge, Colin.

[Thevak]

Sorry to change thread slightly but from where did Alfa/Fiat source the boxer motors for the Suds/33?

[rowan_bris]

Brian

If you remove the brass drain plugs on either side of the block you should get most of it out.

regards
Rowan

[bteoh]

Thanks Col, Rowan,
I should have been more diligent and removed the drain plugs from the block. I guess I took the lazy way out
Was concentrating more on replacing the exhaust system on the car which was a PITA , without a hoist .
Crawling under the car isn't much fun